Wednesday, 26 February 2014

Taking the long route - how I got here...

by Kirstie O'Neill

As you can see from reading through this GEESology blog, geography is indeed a broad discipline covering all manner of exciting areas.  The ways which each of us GEESologists have come to this are equally varied – so here’s my version as a social geographer! 

1970s singer Kenny Loggins
I always loved geography, and reading maps – I had great teachers at school which really helped, although sometimes the singing was a drawback (‘footloose’ by Kenny Loggins sticks in my mind!).  

I knew I wanted to do geography at A-level and did better than expected so was able to study it at University too. I got a place (unexpectedly) at Newcastle University.  Studying geography at University was different to school, and we got to specialise in areas that hadn’t even come up at school – rural geography appealed to me, I just seemed to enjoy and ‘get’ it.  But, I couldn't believe our first fieldtrip was back to West Cumbria and my old school's barn (below) - no exciting field trips anywhere exotic unfortunately!

Bakerstead Barn, Eskdale, West Cumbria - on a rare sunny day!

After university I wasn’t quite sure what I wanted to do, but knew it would be geography and rural based – luckily, the rural community council in Cumbria, Voluntary Action Cumbria, had Lottery funding to train up rural community development workers.  The interview was a baptism by fire, a whole day with the other candidates and being ‘interviewed’ by the staff and trustees all day.  But, I got the job and needed to quickly buy my first car to do the job, and enjoyed a few years back in my native Cumbria doing rural community development.  But all good things must come to an end.

Over the next six years, I moved to Durham County Council, Yorkshire Rural Community Council and finally North Yorkshire County Council all doing rural development stuff.  I was working for North Yorkshire County Council when I saw a PhD advertised – I’d been thinking of doing one for a while, although didn’t realise you could actually get funding to do one.  The one advertised was funded, and was a collaborative research project with the local council – so I had a chat to the people at Hull University.  It sounded really exciting – local food was an area I was really interested in, and the opportunity to learn Italian and getting to do research in Italy didn’t sound so bad either!

               Researching rural development and local food in the Abruzzo region of Italy

So, in 2007 I also gave up my job and went back to University full-time (fieldtrips have improved!), I passed my PhD viva in 2012 (my thesis is available here) and have been lucky to get postdoc positions after the PhD too – I’m about to start a new job at Lancaster University looking at food and whether peoples’ decisions about what to buy include any consideration of sustainability.  This brings my PhD work (food) and my post-doc work (low carbon, green entrepreneurs, sustainability) together and hopefully I’ll get to write something about it soon...

I’d like to continue researching green building (here) and food (here), both of which are really important in relation to sustainability, but as ever, it all depends on what’s around at the end of the next short-term contract!

Wednesday, 19 February 2014

Fieldwork - slippery when wet

By Dr Karen Scott (@DrKarenScott)

Whenever fieldwork is mentioned the first thing that comes to my mind is long summer days walking in t-shirts by lakes or across fields (or Hull council estates as most of my PhD sampling days were spent), maybe even in an exotic location or an overseas field trip. However, it’s no secret this is not always the case, especially in this field where outdoor working is a necessity whatever the weather (much to my parents surprise who thought as soon as the temperature dropped below t-shirt weather, it became slightly chilly or the forecast suggests a bit of drizzle, it would be home time).

In fact I sit writing this having spent 6 hours trudging across the Yorkshire Moors in freezing rain that came at you sideways (no matter what direction you faced) and eating my soggy sarnies sheltering in a gully trying not to fall into a patch of boggy bare peat. And it’s with the recent weather hitting the news, I thought I’d blog about the effects of weather on fieldwork, or more so, how its put up with (I will try to avoid moaning where possible!).

 These pictures were taken within 24 hours of each other

Starting my new job in September (working on a project assessing moorland management on water quality at the University of Leeds, meaning 3-4 field days a week) I was greeted with relatively warm long days with beautiful views across the moors - which I wasn’t shy in sharing, after all it beats the office wall! But this soon changed as winter reared its head. The thing I found most interesting during field work as winter started to set in was how everything changed so quickly and how I had to change how things were done. The lack of daylight was the main issue - having to set off early to squeeze as much daylight into your working day as possible, which is something you don't normally have to think about when you are heading into the office every day. Relatively dry areas of land turned into huge boggy patches that would swallow your wellies before you had a chance to work out which piece of heather you could reach to drag yourself out. You never really find out what kind of land you are safe to walk on / avoid until you’re shin deep in it – I find frosty/snowy days the worst, as there will always be that one bog that has thawed a bit more than the others you have walked across! A lot of the vegetation dies off, which in theory isn’t a bad thing when walking along the flat, but when steep banks become involved that’s when it is time to be cautious as they become quite slippery. I generally approach these with a foot slide or a bum slide, because let’s face it, I’m probably not going to be spending much time on my feet! 

Bleak view for four hours
Chilly day in the field wearing approximately 12 layers!
Due to the change in weather my bag seems to have doubled in weight. This is mainly due to extra batteries for the equipment (they aren't as keen on the weather either), extra clothes (in case I fall in a stream and need a spare pair or it gets too cold and I have to bulk up), a flask containing luke warm tea, extra food (obviously for the cold, and not to cheer me up on bleak days) and extra water samples (with the weather being wetter the streams run more, so I need to collect more to carry home). Gauging the weather forecast in remote areas is always a difficult one. Finding the nearest town to your site seems like a good idea at first, and can be quite uplifting when you are driving to your site, it might looks a bit misty and chilly but generally a decent field day. Until you got up to the tops, turn that corner, and are greeted with snow / blizzards / hail / bears (got to be prepared!). And to finish on my favourite: the waterproofs... They never seem to be 100% dry and after going over a few stone walls they always seem to leak in the worst place.

As much as bad weather can put a damper on fieldwork (no pun intended) I still enjoy the variety it gives my job and the sunny days always outweigh the wet and the cold ones. Plus there are always others ways to brighten up the wet and windy days where it’s impossible to stand upright and even your waterproofs have given up, such as cake.

Perfect end to the day!

Wednesday, 12 February 2014

An Unexpected (Academic) Journey

By Lucy Clarke (@DrLucyClarke)

As mentioned in my previous posts I am a fluvial geomorphologist. I am interested in the processes that operate on the Earth’s surface and especially those that occur in fluvial (or ‘watery’) environments, although at the moment I have moved into exploring frozen water, looking at glacial change in Antarctica (which I will blog more about in the coming year). So how did I come to be doing this?

Always happy to be on a river!
I can honestly say that working in academia wasn’t my childhood dream – I wanted to be a vet, but as I have an allergy to virtually all animal hair that was never a realistic occupation! The main reason for my lack of ambition in academia was because I didn’t realise it was even an option, I came from a family where no one had ever been to university so I didn’t know anything about how it worked or that people like me could make a career of it. But my parents were determined that myself and my sister would break this trend and get a degree and so through school it became my aim to go to university. Loving the outdoors and exploring different places, geography had always appealed to me, so I managed to win a position studying for a BSc degree in Geography at the University of Durham and going there changed everything for me. I absolutely loved doing my undergraduate degree and that is when my passion for physical geography really took hold, and it opened my eyes to all the possible options for my future that I had never considered before.

On finishing my degree I wanted to see some more of the world and so I won a place on a research Masters at the University of Otago in New Zealand and moved Down Under. My research specialised in sediment transport in rivers and used aerial photography and field techniques to explore spatial and temporal trends. This experience was amazing as I got to learn different geographical and surveying techniques, plus, writing a 40,000 word thesis gave me a good insight into the research process and all of this in one of the most impressive and beautiful places I’ve ever visited and which I was fortunate to explore thoroughly in the couple of years I lived there.

Once I had completed my thesis I took a circuitous route back to the UK, visiting new found friends in Australia and Canada for a few months before coming back to reality. On my first day back I checked the job websites and found an advertisement for a PhD at the University of Exeter using image analysis of experimental alluvial fans (see my blog post from 28 August 2013) supported by fieldwork in New Zealand – it sounded perfect for me and within a week of my return I had been down to the South West for an interview and was offered the PhD. And so I spent the next 4.5 years in Exeter; I got my PhD and during this time I took every opportunity to attend conferences, assist on field trips (in the UK and abroad), undertake teaching and generally make the most of my time as a postgraduate. I then worked in the department on a teaching and a research fellowship and realised that a career in academia was what I wanted to do.

Me and my PhD physical model - many hours were spent in the lab
Since then I have been on the early career researcher cycle, an increasingly common experience for ‘young’ academics trying to carve out a career. Some people are lucky enough to stay in the same institution or just move once before getting a permanent position but my path has followed a different route. I took a teaching lectureship at the University of Dundee, before moving back to my native Yorkshire for a postdoctoral position at the University of Hull for a couple of years and now I am based in Cambridge at the British Antarctic Survey – at least for the next 15 months. Although moving around so much can cause a certain amount of instability in my life, it has been a fantastic opportunity to gain experience of different institutions and I have made friends and colleagues in each place and through this developed research ideas that I am excited to progress in the future.

Come rain or shine it's great to get out in the field
So, my journey into academia may have been unexpected but I couldn’t be happier to be where I am now and wouldn’t be doing anything else! I have no regrets over my career (other than the usual academic regret of not having written enough papers, but I’m working on this!) and have had some amazing experiences that I wouldn’t change. I am still hopeful for the elusive permanent position and working hard to make it happen as soon as I can, but who knows where that will be. I have no idea where I will end up next, but I am excited to find out and I’ll keep you posted on my progress through the blog…

Wednesday, 5 February 2014

What's that coming over the hill...?

Understanding how pyroclastic density currents behave through time and space.
by Rebecca Williams (@volcanologist)

Pyroclastic density currents are flows of searing hot gas, ash and rocks that swoop down the sides of a volcano during the most violent eruptions. They can travel at speeds of up to 450 mph and can be as hot as 1000°C. Historically, they have been responsible for over 90,000 deaths, and so are the most deadly volcanic phenomenon.  In order to try and reduce the risk to people from these hazardous flows, we strive to understand how they behave. The trouble is though, is that they are very difficult to observe. Even small flows, such as those recently seen at Sinabung (Indonesia) and Tungurahua (Ecuador) volcanoes are hidden in a cloud of ash. The largest types of these currents however, have not been observed at all, and no instrument exists that can be deployed (and survive) to record them. So, we try to understand the processes in these currents by studying their deposits.
A typical ignimbrite as found on Tenerife. You can study the changes in size and quantity of pumices (yellowish, bright bits) and lithics (dark bits) to infer current dynamics. You can also interpret sedimentary features such as low-angle cross bedding (on a level with the scale) or if the deposit is massive (as it is towards the top of the photo). Photo credit: Rebecca Williams
 The deposit of a pyroclastic density current is called an ignimbrite. We can infer quite a lot about a current by studying an ignimbrite – such as which direction it was going, whether it was turbulent and dilute or whether the flow was dense and more full of blocks of rocks than it was gas and ash. At a single location, we can study the vertical section through a deposit and see how the ignimbrite changes from the bottom to the top. This tells us how the current was changing from its start (the bottom of the deposit) to its end (the top of the deposit), as the deposit builds up through time, recording the changing dynamics of the flow. What we need to know though, is how the current behaves through time everywhere it flows. Did it flow down that valley at the same time that it flowed down this one? Did it go over that big hill at the start of the eruption, or did it have to bury some of the topography to make it easier to flow over? Of particular interest are the very large flows that form a circular deposit around a volcano – are these formed by a radially expanding current that flows in all directions around a volcano all at once? This is much harder to do: there is often nothing in the deposit that tells us where we are in time in the current's duration. So, we can’t join up all those vertical sections to understand how the current behaved through time and space all around the volcano. That is till now, as published in the February issue of Geology.
A 'typical' section of the Green Tuff Ignimbrite - it's not typical! You can see it doesn't look like the Tenerife ignimbrite - that is because it is welded. The ash and pumice were so hot when they were deposited they welded together into glass. You can still see lots of primary sedimentary features though, including imbrication as seen here - the current was flowing from right to left. Photo credit: Rebecca Williams

The study here maps out the chemical composition of an ignimbrite which was deposited from a single, sustained pyroclastic density current and reveals how the current behaved through time and space. The ignimbrite used in the study, The Green Tuff Ignimbrite on Pantelleria, Italy, is a circular ignimbrite. It is chemically zoned, that is the chemical composition of the deposit is different at its top than it is at the base, and the composition changes gradually between the two extremes. This is because the magma chamber that the current was erupted from was zoned. At the top of the chamber the magma was more evolved than the magma at the bottom. So, when the volcano erupted it progressively withdrew magma of gradually changing composition and this was recorded in the volcanic deposits. This then, gives us a timeline through those deposits – we can say whether that chemistry was erupted at the beginning, the middle, or the end of the eruption.

The type section of the Green Tuff Formation and representative graphs of the changing composition. Copyright Geology. Full figure caption:
  What we found in the Green Tuff was that the chemical change was gradual, so we were able to divide the unit into 8 different compositions, and these were equivalent to 8 different time steps through the eruption. Once we’d determined this chemical stratigraphy, and defined it at a type locality (a place that records the entire compositional change) we then went and mapped the entire ignimbrite. I spent over 6 months spread over 3 years logging, mapping and sampling the Green Tuff Ignimbrite and analysed over 500 samples to determine their chemical composition. I then input all this data into ArcGIS so I could see what the spatial extent of each of the 8 compostional zones were. I produced maps of these different zones and these maps represent the footprint of the current that formed the Green Tuff at a snapshot in time during the eruption.
Footprint maps of the Green Tuff pyroclastic density current based on zironium (Zr) compositional zones. Copyright Geology. Full figure caption:
By analysing these maps we realised that, contrary to assumption, the current did not flow in all directions all at once. Instead, at the start of the current's duration it didn’t get very far at all, and only flowed in certain areas around the island. As the current continued it flowed further in more directions, but was often deflected or reflected around topographic barriers such as hills and old caldera walls. However, at the current's peak, it DID flow in all directions all at the same time. If there had been humans living here at the time, there would have been no escaping the devastating currents. The current continued, but the directions it travelled in decreased and it wasn’t able to go as far. It stopped being able to top over those hills and eventually decreased til it was able to flow only short distances from the vent before stopping altogether. We think that this all happened within about one and a half hours.

This has changed how we think about pyroclastic density currents and will impact on the way we model them for hazard assessments. We should think about these currents as dynamic, and able to change rapidly – each of the 8 zones represents only around 11 minutes. A current that was initially quite slow, restricted to a small area and unable to flow up hills, changed and was able to flow in all directions and over 500 m hills in less than an hour. 

The Green Tuff ignimbrite drapes the La Vecchia caldera wall - both the inward dipping caldera scarp and the seaward-dipping older stratigraphy - at Scauri, Pantelleria. Photo credit: Rebecca Williams
On the other hand, without knowing that the current changed through time, we might have overestimated how big it was. You can use the maximum distance that the current travelled and the volume of the deposit to estimate how much material was coming out of the volcano with time (mass flux). If we had used the maximum values and assumed that was what the current was like for its entire duration, we would have massively overestimated the eruption's mass flux.

Zoned ignimbrites such as the Green Tuff are not rare, therefore we hope that this technique can be applied to other deposits so we can continue to advance our understanding of pyroclastic density currents. 

This blog is a summary of this open-access paper:
Williams, R., Branney, M.J., Barry, T.L., 2014. Temporal and spatial evolution of a waxing then waning catastrophic density current revealed by chemical mapping. Geology. 42, 2, 107-110.